1. Field of the Invention
The present invention relates to a lamp assembly, and particularly to a light emitting diode lamp assembly employed in a direct type backlight module of a liquid crystal display.
2. Discussion of the Related Art
Typically, light emitting diodes (LEDs) are preferred over other types of light sources because LEDs exhibits low energy consumption, long service life, and other advantages. Therefore, LEDs are widely used as light sources.
FIG. 1 illustrates a typical LED lamp assembly 10 using LEDs as a light source. The LED lamp assembly 10 includes a housing 11, a printed circuit board 12, a plurality of side-lighting type LEDs 13, a light reflective module 14, a plurality of circular reflective layers 15 and a lamp cover 16. The housing 11 is an elongated, hollow structure having an opening 112. The LEDs 13 are arranged apart and electrically connected to the printed circuit board 12. The printed circuit board 12 with the LEDs 13 is disposed on a bottom surface of the housing 11. The light reflective module 14 includes a rectangular bottom reflective plate 144 and four connecting sidewalls 142 extending from a periphery of the bottom reflective plate 144. The bottom reflective plate 144 defines a plurality of through holes 146, configured for allowing the light-emitting portions of the LEDs 13 to pass through. The light reflective module 14 can be correspondingly mounted into the housing 11 via the opening 112. The circular reflective layers 15 are positioned at the tops of the LEDs 13 respectively. The lamp cover 16 is fixed on the opening 112 of the housing 11. Light from the light-emitted portions of the LEDs 13 is substantially reflected at the sidewalls 142 and the bottom reflective plate 144, finally output from the lamp cover 16. With the help of the light reflective module 14, an efficiency of utilization of light energy of the LED lamp assembly 10 is increased.
Nevertheless, the brightness above the LEDs 13 of the LED lamp assembly 10 is decreased due to the light reflection off of the circular reflective layers 15, and a plurality of dark areas between the two adjacent LEDs 13 still occur. Accordingly a uniform brightness of the LED lamp assembly 10 is low.
What is needed, therefore, is an LED lamp assembly which have a uniform brightness.